Costa Rica Guide
Guanacaste
Parque Nacional Palo Verde
About 30km west of Cañas on the northern bank of the Río Tempisque lies the PARQUE NACIONAL PALO VERDE (daily 8am–4pm; $6), created in 1982 to preserve the habitat of the migratory birds that nest in the estuary of the Tempisque and a large patch of relatively undisturbed lowland dry forest. With a distinctive topography featuring ridged limestone hills – unique to this part of the country, and attesting to the fact that certain parts of Guanacaste were once under water – the park shelters about fifteen separate ecological habitats. From December to May, Palo Verde can dry out into baked mud flats, while in the wet season, extensive flooding gives rise to saltwater and freshwater lakes and swamps. Following the wet season, the great floodplain drains slowly, creating marshes, mangroves and other habitats favoured by migratory birds. Little visited by tourists, the park is mainly of interest to serious birders, but what you see depends on the time of year – by far the best months are at the height of the dry season (Jan– March), when most of the 250 or so migratory species are in residence. In the wet season, flooding makes parts of the park inaccessible.
The park is home to one of the largest concentrations of waterfowl in Central America, both indigenous and migratory, with more than three hundred species of birds, among them the endangered Jabirú stork and black-crowned night heron. Further from the river bank, in the tree cover along the bottom and ridges of the limestone hills, you may spot toucans, and perhaps even one of the increasingly rare scarlet macaws. At evening during the dry season, many birds and other species – monkeys, coatis and even deer – congregate around the few remaining waterholes; bring binoculars and a torch. Note, though, that you shouldn't swim in the Río Tempisque (or anywhere else), as it's home to particularly huge crocodiles – some, according to the park rangers, are as much as five metres long.
From the administration building, two trails lead up to the top of hills, from where you can see the expansive mouth of the Río Tempisque to the west and the broad plains of Guanacaste to the east. A number of other loop trails, none more than 4km long, run through the park. The shortest of the trails, at just 300m, is Las Calizas; others include El Manigordo ("ocelot"; 1.5km), El Mapache ("raccoon"; 2km) and El Venado ("deer"; 2km), all of which give you a good idea of the landscape and a chance of viewing the animals after which they're named. You've also got a good chance of seeing collared peccaries, abundant in this area, or a coatimundi, which you may see or hear foraging in the undergrowth. White-tailed deer also live here, but they're very shy and likely to dart off at the sound of your approach.
For longer treks, try the Bosque Primario trail (about 7km), through, as the name suggests, primary forest cover. You can also walk the 6km (dry season only) to the edge of the Río Tempisque from where you'll see the aptly named Isla de los Pájaros (Bird Island). Square in the mouth of the river, the island is chock-full of our feathered friends all year, with black-crowned night herons swirling above in thick dark clouds. Many hotels and tour agencies in the province offer boat trips around the island, but landings are not permitted, so you have to content yourself with bird-spotting and taking photographs from the boat.
The Organization for Tropical Studies (OTS) has a field station at Palo Verde, originally set up for comparative ecosystem study and research into the dry forest habitat. If you contact their San José office ( 
240-6696, 
240-6783, 
www.ots.ac.cr ) in advance you may be able to stay in their rustic field station, next door to the administration building providing it's not full of scientific researchers. Accommodation (Price: $76-100) is in clean dormitories, and meals are included in the rate. There's also a basic but perfectly comfortable albergue at the ranger station, about 10km from the entrance. The six rooms here each contain six bunk beds ($15 per person), including mosquito nets and fans, and meals are available (breakfast $3; lunch and dinner $6). You can also camp ($2 per day; 671-1290 or 671-1062) at the small site next to the administration building, where there are lavatories, but it's best to call ahead to check that there's space. If there's not, there are several accommodation options along the Interamericana in and around Bagaces.